1. Field of the Invention
The present invention relates generally to magnetic heads for hard disk drives, and more particularly to the fabrication of a non-magnetic electrically conductive write gap structure between the magnetic poles of a write head portion of such magnetic head.
2. Description of the Prior Art
As is well known to those skilled in the art, standard magnetic heads include write head elements that include two magnetic poles, commonly termed the first magnetic pole (P1) and the second magnetic pole (P2) poles, with a write gap layer formed between them. During a data recording procedure, the passage of magnetic flux across the write gap between the two poles creates a magnetic field which influences a thin film layer of magnetic media on a hard disk that is located proximate the magnetic head, such that the changing magnetic flux creates data bits within the magnetic media. In a longitudinal magnetic head the size of the data bit is substantially determined by the size of a magnetic pole tip of the second magnetic pole, referred to herein as the P2 pole tip.
The continual quest for higher areal data recording densities of the magnetic media demands smaller bit sizes which may be achieved by reducing the thickness of the write gap layer and the size of the P2 pole tip. In the typical prior art magnetic head, the write gap material consists of a non-conductive, non-magnetic material such as alumina. The P2 pole tip is formed utilizing photolithographic techniques in which an electrically conductive seed layer comprised of a magnetic material, such as NiFe, is deposited upon the alumina write gap layer, and a patterned photoresist having a pole tip trench formed therein is fabricated upon the electrically conductive seed layer. Thereafter, the P2 pole tip is electroplated within the pole tip trench utilizing the electrically conductive seed layer to conduct electroplating current. Following the electroplating process the photoresist and uncovered seed layer is removed. As a result, the remaining seed layer that is disposed beneath the electroplated pole tip effectively becomes part of the pole tip through which magnetic flux flows. The thickness of the seed layer therefore contributes to the overall thickness of the P2 pole tip.
In more advanced magnetic heads, the magnetic pole tip material is formed with significantly improved magnetic properties than can be achieved in the magnetic seed layer. The improved magnetic properties are desirable to provide increased magnetic flux flow at greater magnetic flux densities in order to write smaller data bits to the magnetic media. In this situation, the relatively ordinary magnetic properties of the magnetic seed layer are detrimental to the desired magnetic flux flow through the P2 pole tip. The magnetic head of the present invention includes a non-magnetic, electrically conductive seed layer which aids in obtaining the desired magnetic flux flow through the P2 pole tip.